Intraoperative electromagnetic apparatus and related technology

Abstract

An apparatus capable of applying a first electromagnetic signal, e.g. an optical signal, to a tissue portion is described. The apparatus is also capable of applying a second electromagnetic signal from a different portion of the electromagnetic spectrum, e.g. a microwave signal, to the tissue portion. Signals returned from the tissue portion and related to the first electromagnetic signal are analysed to give a first evaluation of the physical and biophysical characteristics of the tissue portion. Signals returned from the tissue portion and related to the second electromagnetic signal are also analysed, and a final evaluation of the physical and biophysical characteristics of the tissue portion is produced, informed by the first evaluation and the analysed second signal.

1 . A method of evaluating physical and biophysical characteristics of a tissue portion, the method comprising the steps of:
 applying first and second electromagnetic signals to the tissue portion, the first and second electromagnetic signals from different portions of the electromagnetic spectrum;   analysing a first signal returned from the tissue portion and related to the first electromagnetic signal to give a first evaluation of the physical characteristics;   analysing a second signal returned from the tissue portion and related to the second electromagnetic signal; and   producing a final evaluation of the physical characteristics informed by the first evaluation and the analysed second signal.   
   
   
       2 . The method of  claim 1 , wherein the step of analysing the first and second signals returned from the tissue portion is informed by knowledge of the electromagnetic signals applied to the tissue portion. 
   
   
       3 . The method of  claim 2 , wherein the first electromagnetic signal is from the optical portion and/or infra-red portion of the electromagnetic spectrum. 
   
   
       4 . The method of  claim 3 , wherein the first electromagnetic signal has a wavelength of 0.4 μm to 4 μm. 
   
   
       5 . The method of  claim 2 , wherein the second electromagnetic signal is from the low frequency and/or microwave portion of the electromagnetic spectrum. 
   
   
       6 . The method of  claim 5 , wherein the second signal has a frequency of 0.1 MHz to 10 GHz. 
   
   
       7 . The method of  claim 1 , wherein the first and second electromagnetic signals are applied to at least partially overlapping physical areas or partially overlapping physical volumes of the tissue portion. 
   
   
       8 . The method of  claim 1 , further comprising providing a user with a visible and/or audible output representative of one or more characteristics of the final evaluation. 
   
   
       9 . The method of  claim 1 , wherein the first and/or second electromagnetic signals have one or both of: time-varying frequency; and a plurality of signals at different frequencies transmitted and analysed simultaneously, within the first and second portions of the electromagnetic spectrum. 
   
   
       10 . Apparatus for evaluating physical and biophysical characteristics of a tissue portion, the apparatus comprising:
 first and second electromagnetic signal generating units, first and a second electromagnetic signal detecting units, and first and second electromagnetic signal analysing units, wherein:   said first and second electromagnetic signal generating units are operable to apply first and second electromagnetic signals to the tissue portion, the first and second electromagnetic signals from different portions of the electromagnetic spectrum;   said first electromagnetic signal detecting unit is operable to detect and analyse a first signal returned from the tissue portion and related to the first electromagnetic signal to give a first evaluation of the physical characteristics;   said second electromagnetic signal detecting unit is operable to detect and analyse a second signal returned from the tissue portion and related to the second electromagnetic signal; and   the apparatus further comprising a final evaluation unit operable to produce a final evaluation of the physical characteristics informed by the first evaluation and the analysed second signal.   
   
   
       11 . The apparatus of  claim 10 , wherein the analysis of the first and second signals returned from the tissue portion performed by the first and second signal analysing units is informed by knowledge of the of the electromagnetic signals applied to the tissue portion by the first and second signal generating units. 
   
   
       12 . The apparatus of  claim 11 , wherein the first signal generating unit is operable to apply a first electromagnetic signal from the optical portion and/or infra-red portion of the electromagnetic spectrum. 
   
   
       13 . The apparatus of  claim 12 , wherein the first signal generating unit is operable to apply a first electromagnetic signal from the portion of the electromagnetic spectrum having wavelength of 0.4 μm to 4 μm. 
   
   
       14 . The apparatus of  claim 10 , wherein the second signal generating unit is operable to apply a second electromagnetic signal from the low frequency and/or microwave portion of the electromagnetic spectrum. 
   
   
       15 . The apparatus of  claim 14 , wherein the second signal generating unit is operable to apply a second electromagnetic signal from the portion of the electromagnetic spectrum having frequency of 0.1 MHz to 10 GHz 
   
   
       16 . The apparatus of  claim 10 , wherein the first and second signal generating units are operable to apply first and second electromagnetic signals to an at least partially overlapping physical area or partially overlapping physical volume of the tissue portion. 
   
   
       17 . The apparatus of  claim 10 , wherein the first signal generating unit comprises a first signal generator coupled by a first signal transmission portion to a first signal outlet, and/or the second signal generating unit comprises a second signal generator coupled by a second signal transmission portion to a second signal outlet. 
   
   
       18 . The apparatus of  claim 17 , wherein the first and/or signal outlets are integrated in a probe head. 
   
   
       19 . The apparatus of  claim 18 , wherein the probe head is integrated with an endoscope. 
   
   
       20 . The apparatus of  claim 17 , wherein the first signal transmission portion comprises an optical fibre. 
   
   
       21 . The apparatus of  claim 17 , wherein the first signal generating unit comprises a plurality of first signal generators coupled by a plurality of first signal transmission portions to a plurality of first signal outlets. 
   
   
       22 . The apparatus of  claims 17 , wherein one or more of the first transmission portions transmits a first signal returned from the tissue portion and related to the first electromagnetic signal to the first signal detecting unit. 
   
   
       23 . The apparatus of  claim 17 , wherein the second transmission portion comprises a co-axial cable. 
   
   
       24 . The apparatus of  claim 17 , further comprising one or more electrodes arranged to transmit a second signal returned from the tissue portion and related to the second electromagnetic signal to the second signal detecting unit. 
   
   
       25 . The apparatus of  claim 24 , wherein the electrode or electrodes are arranged between the conductors of the co-axial cable. 
   
   
       26 . The apparatus of  claims 17 , wherein, the arrangement of one or more of: the co-axial cable; the signal outlets and the electrodes in the probe head in cross section exhibit one or more of: circular; rotational; and reflective symmetry. 
   
   
       27 . The apparatus of  claim 10 , further comprising a user interface unit operable to provide a visible and/or audible output representative of one or more characteristics of the final evaluation produced by the final evaluation unit. 
   
   
       28 . A method of determining disease state in a tissue portion, the method comprising the steps of:
 producing a final evaluation of physical characteristics of the tissue portion using the method of  claim 1 ;   comparing the final evaluation to corresponding characteristics of samples in a library of reference samples of known disease state to find a closest match; and   determining a disease state of the tissue portion as that corresponding to the disease state of the reference sample which is the closest match.   
   
   
       29 . A method of reconstructing a representation of a tissue portion, the method comprising the steps of:
 producing a final evaluation of physical characteristics of the tissue portion using the method of  claim 1 ;   comparing the final evaluation to a previously established model of physical properties of tissue types; and   reconstructing a representation of the tissue portion based on the comparison of the final evaluation and the model.   
   
   
       30 . A method of treating a diseased part of a tissue portion, the method comprising:
 applying electromagnetic ablation to the diseased parts of the tissue portion.   
   
   
       31 . The method of treating a diseased part of a tissue according to  claim 30 , the method comprising the further step of: either (a) determining disease state or states in parts of the tissue portion using the method of  claim 28 ; or (b) reconstructing a representation of the tissue portion and identifying in the reconstructed representation disease state or states in parts of the tissue portion.